Presentation Layer implementation: First draw a static interface (1 defines the component that the interface needs to display, 2 initializes the component and sets the component's properties, 3 puts the component into a panel, puts the panel into a frame), and the writing interface implements the dynamic function through the code.
steps to show data: 1,i invokes the logical interface to get the data that needs to be presented. 2 Convert data. 3, set the data to display on the component.
Basic knowledge Notes for Web applications
MIME is used to specify the type of content
DNS domain name Resolution service resolves the domain name to IP.
URL: protocol name + domain + Port +web context (if the root is the tone of the web context)
the default port for the Htttp protocol is 80 (can be omitted).
Getting Started with Servlets, requesting answer mode notes
a servlet is a small application on a component or server that is executed on the server side. (a small program means that it cannot run independently of a container.)
The server does not retain client information. The Serlet is used to receive a TTP request, generating an HTTP response.
The servlet runs in the Web container, and the Web container is a JVM that provides the component runtime Environment control lifecycle.
when to use abstract classes: both constrain the behavior of subclasses and provide public functionality for subclasses. (Separation and change)
Getting Started with Servlets, requesting answer mode notes
Use abstract classes: both constrain the behavior of subclasses and provide common functionality for subclasses.
Getting Started with Servlets, requesting answer mode notes
1servlet is a Java component that runs on a Web server and is responsible for processing requests and responses.
The Web container runs the servlet and is a special JVM.
HTTP is connection-oriented, no connection, no long connection, no status.
Javaweb Study Notes 1
